Is it possible, in principle, to find compelling evidence that God exists? Or, as a supernatural being, is God beyond proof?

There are certain aspects of God which are definitely open to inquiry. For example, any incident in the physical world attributed to the work of God can be investigated. We can examine miracles, test the efficacy of prayer, research stories of visions and faith healing, etc.

God’s properties can also be tested with logic — if any two of His proposed properties are logically inconsistent, then we can be certain that one or both of them is incorrect.

But while testing physical manifestations and defining potential properties might help us set limits on what God might be, they do nothing to prove whether or not the divine being actually exists.

There are large difficulties facing someone who wants to prove that God exists. For example, any event that appears to be a sign of divine existence could have a more likely, completely non-supernatural explanation. For example, it is possible that God created the universe, but it is also possible that the universe came into being through a natural process (and even a process that is currently unknown might be judged a more likely explanation than an all-powerful deity).

Another difficulty is that God is immaterial, and since science can only investigate material things there is no way that science can directly investigate the existence of God.

Recognizing these difficulties, there are three ways you might be compelled to believe that a deity does indeed exist.

First, evidence could appear that cannot conceivably be explained without appeal to a deity. For example, it might be discovered that no matter what language you speak you can find the text of a lengthy religious work unambiguously encoded in the digits of pi. It would be hard to conceive of a non-supernatural explanation of such a thing.

Second, you could receive a divine revelation. God could use supernatural power to force you to believe that He exists. People might think you had gone mad, and your experience would not be compelling to others, but you would have no choice but to believe that God exists.

And third, an unassailable argument for the existence of God might come to light some time in the future.

Now let’s imagine that through one of these methods you become convinced that a deity exists. Can you prove that this deity is indeed God and not some other supernatural being just pretending to be God? Likely not. There is no trick of logic or science that would be guaranteed to wrest the truth from a supernatural being.

So even if you were compelled to believe that a deity existed, it would still be an act of faith to conclude that this deity was God.